The first documented sighting of a group of bowhead whales at the mouth of the Churchill River in Canada

In the summer of 2020, researchers at the University of Manitoba installed a time-lapse camera overlooking the mouth of the Churchill River. The goal of their research was to understand the interaction between beluga whales and marine vessels. But it was unexpected that they filmed. A group of bowhead whales, a phenomenon that has never been recorded in this area.

The Bowhead Whale is the only berries whale that lives all year round in the Arctic. Canada’s waters include the population of Greenland (EC-WG) in western Canada, two populations found from northern Hudson Bay to Greenland, and the Beringchukchi-Beaufort population found in waters from northwest Canada to Russia.

Commercial whaling from the 15th to 19th centuries severely depleted the EC-WG population. After commercial whaling ended in 1915, the population began to recover, but figures appear to have been stagnating lately.

A recently published paper by Veronica Coppolaro and colleagues highlights the first recorded sightings of a group of bowhead whales at the mouth of the Churchill River, highlighting the rarity of the outbreak based on historical data. This paper has been published in the Journal of Polar Biology.

Emma Authentic, Emma Authentic, and M.Sc, graduate of the University of Manitoba. Copporororo was conducting surveillance studies of beluga whales when the sighting occurred. While reviewing the time-lapse photos, Authentico noticed two dark figures in one of the images. Coppororo recalls Authentico saying, “There are large log-like branches in the water.”

They then heard reports from a local tour guide for the Bowhead Whale at the mouth of the estuary.

“If the date on the report matches the photo, it’s possible that you’ve photographed a bowhead whale,” Authentic said. The pair then carefully identified species in the images and worked to contextualize observations. The goal of their paper was to determine how common such sightings were in the past and to investigate why bowhead whales were in the area.

Apart from the summer migration of Belgas in West Hudson Bay, no other whale species are known to frequently appear at the mouth of the Churchill River.

“The estuary is shallow, and for most parts it is less than three meters,” explains Copporororo. “And the bowhead whales are big. They are 18 to 18 meters long.”

Furthermore, when outside the normal range, bowhead whales are usually observed alone. “They don’t travel in groups in general,” Coppororo emphasizes.

Given the rarity of this sighting, researchers conducted a review of bowhead whale sightings along Manitoba’s coast, compiling literature, anecdotal accounts, and observations from locals and researchers. They have only found ten bowhead whales since 1900.

Why was the whales here south?

One hypothesis is that bowheads have moved south to change habitats caused by climate change.

Another possibility is that the EC-WG population is growing and the range will gradually expand due to both climate change and population recovery.

Furthermore, the decline in sea ice has led to an increase in ORCA sightings in Hudson Bay. As a result, the bowhead whales were able to use the mouth of the estuary as a shelter to escape predation.

“They might have also been looking for food,” Coppororo explains. Due to changes in the tide, the estuary provides a rich food for both Baleen and dental whales.

Whales use warm shallow water from the bay to shed and remove their skin, just like Belgas does.

There are many reasons for the existence of bowheads at the mouth of the estuary, but one hypothesis is that the pair discovered in 2020 are calves and cows.

What will the future hold?

“Since 2000, there has been an increase in the sightings of bowhead whales at the mouth of the estuary,” explains Coppororo. However, increasing vessel traffic could affect the future presence of whales.

The EC-WG population has been designated as a “special concern” by the Committee on the Status of Endangered Species of Wildlife in Canada (Cosewic). If the estuary becomes a hot spot for these whales, additional management strategies may be required. This includes establishing a limit on the size and speed of vessels at the estuary.

Copporolo hopes that the findings of their paper will help raise awareness of changes and changes in marine ecosystem habitats.

“There’s something special when these animals come. There’s a big news about the town being shared with everyone. It’s part of Churchill and the wonders of adventure,” Authentico said. “Science is simply about discovering more about the world we live in.”